1. Field of the Invention
This invention relates to condensates of fatty acids and hydroxyalkyl polyamines and their use as opacifiers and thickeners in surfactant-containing compositions such as liquid washing preparations.
2. Description of Related Art
Liquid surfactant-containing compositions are used, for example, for washing fabrics or as shampoos for washing hair. In many cases, these compositions contain active ingredients which impart antistatic properties and body, respectively, to the fabrics and hair washed with them. The most common active ingredients are quaternary ammonia- or imidazoline-based cationic compounds containing 2 long-chain C.sub.10 -C.sub.24 groups in the molecule. In combination with anionic surfactants, however, the cationic active ingredients can only be used with considerable limitations because the cationic compounds weaken the effect of the anionic surfactants and vice-versa. For this reason, the surfactants present in such compositions are generally nonionic surfactants which, in many cases, are specially selected to obtain an optimal combination of properties. German Application No. 2 817 834 for example relates to liquid compositions containing special combinations of specially selected nonionic surfactants and cationic active ingredients. Attempts to produce compositions having a high content both of surfactants and of cationic active substances are attended by problems attributable to a marked increase in viscosity with increasing concentration of the ingredients. Concentrates of the type in question lose their fluidity at temperatures of the order of +5.degree. C. On the other hand, they lose their stability and tend to separate in the event of prolonged storage at temperatures of the order of +40.degree. C. These difficulties can be avoided or reduced by using, instead of the outstandingly effective quaternary ammonium compounds containing 2 long alkyl residues, those containing 2 long C.sub.10 -C.sub.24 alkenyl residues which show better solubility and dispersibility in the aqueous system than the compounds containing 2 long alkyl residues. Particularly soluble compounds containing 2 long alkenyl residues are derived from imidazoline. One typical representative is 1-methyl-1-oleylamidoethyl-2-oleylimidazolinium methosulfate commercially available as REWOQUAT W 3690, a trademarked product of REWO Chemische Werke GmbH, Steinau, Federal Republic of Germany. With compounds of this type, it is possible to prepare liquid compositions which contain up to 70% by weight of nonionic surfactants and, depending on their surfactant content, up to 35% by weight of a quaternary ammonium compound. Up to one quarter of the quantity of the quaternary ammonium compound may be replaced by compounds derived from ammonia, for example by ditallow alkyl dimethylammonium salts.
Although the compositions described above show good flow properties at low temperatures and high stability in storage at elevated temperature, they lack "consistency" which, to the consumer, is a sign of a high concentration of active ingredients. In the context of the invention, "consistency" is understood to be a viscosity of the compositions of from 300 to 1500 mPa.s at +5.degree. to +40.degree. C. combined with opacity.
U.S. Pat. No. 3,775,316 relates to a softening finishing composition for washed laundry; and the relevancy of this patent to the present invention is described below in the description of the invention.